In a posting to its online support center, Microsoft said: "this security issue could make it possible for an attacker to take control of a WINS server remotely." As of Nov. 26, however, Microsoft said it didn't know of any actual exploit of the possible vulnerability.
Microsoft recommended that network administrators remove WINS if it's not needed, and/or block TCP and UDP ports 42 at the firewall.
WINS is often used by enterprises for name registration and name resolution functions, so it may be impossible to disable without impacting the network. Blocking TCP/UDP ports 42, however, will guard the systems behind the firewall from possible attack.
Danish security firm Secunia tagged the vulnerability as "moderately critical," while the SANS Institute's Internet Storm Center said in an advisory that until Microsoft releases a patch, its best advice was to follow Microsoft's and block unneeded ports, such as port 42.
"So far, we doubt this will be a huge thing," said the Center, "but we might be wrong."
The Storm Center also blasted the researcher, Nicolas Waisman, who reported the vulnerability, claiming that his disclosure prior to a patch being available was "irresponsible."
More information on steps to take to protect WINS-running servers can be found on the Microsoft Web site.